Illinois security deposit law, in plain English

The 30-day rule

A landlord who wants to keep any part of your deposit for damage has to give you an itemized statement of that damage within 30 days of you vacating. The statement lists each item and the estimated or actual cost to repair or replace it, with paid receipts attached or to follow.

If they send estimates rather than receipts, the receipts have to follow within 30 days of that statement.

The part almost nobody knows: it only applies to five or more units

The Act applies to a lessor of residential real property containing five or more units. That threshold is the most misunderstood thing about Illinois deposit law.

It matters a great deal around here. Much of the Machesney Park, Roscoe and Rockton rental stock is duplexes, single-family houses and small conversions owned by individual landlords. If yours owns fewer than five units, the statutory 30-day clock does not apply to them, and your lease plus ordinary contract law governs instead.

That does not mean a small landlord can keep your deposit for no reason. It means your leverage comes from your lease and your evidence rather than from this statute.

What happens if they miss the deadline

If no statement and no receipts arrive as required, the landlord must return the deposit in full within 45 days of the date you vacated.

A landlord who refuses to supply the itemized statement, or supplies one in bad faith, and fails to return the deposit in time can be liable for twice the amount of the deposit plus court costs and reasonable attorney fees.

Cleaning is not damage

The Act concerns damage beyond normal wear and tear, and costs reasonable to restore the unit to the same condition.

This is why a documented professional clean is worth more than the clean itself. It turns a vague argument about whether the place was dirty into a dated invoice and a set of photographs.